Katinka Domotorffy, the head of Goldman Sachs Group Inc's quantitative investment strategies group, will leave the bank at the end of the year, according to an internal memo, as one of its biggest hedge funds continues to suffer from weak performance.

Domotorffy is a Goldman veteran who joined the bank in 1998 as a portfolio manager and researcher.

She took on her most recent title as chief investment officer and head of QIS within the asset management division in 2009 when Mark Carhart and Raymond Iwanowski, co-founders of Goldman's prominent Global Alpha Fund hedge fund, retired.

Armen Avanessians will be taking over as head of the global quantitative business, according to the memo obtained by Reuters that was sent by Timothy O'Neill and Edward Forst, co-global heads of investment management.

Goldman also hired Ron Hua as a partner to serve as chief investment officer and head of quantitative equity alpha businesses.

The Global Alpha Fund is down 12 percent this year, according to sources familiar with the matter.

As a quantitative hedge fund, Global Alpha hops in and out of positions quickly and uses arbitrage strategies to heighten gains. The fund gained prominence in the boom years leading up to the financial crisis and was seen as a proxy for Goldman's market savvy, but has been riddled with losses and redemption requests since then.

The broader hedge fund industry was sacked by losses in August due to heightened volatility across nearly all markets and strategies. The average hedge fund was down 2.32 percent last month, according to Hedge Fund Research.

Avanessians is a partner who joins QIS from Goldman's securities division. He was involved in quantitative, electronic, rules-based and analytical businesses, according to the memo.

Hua joins the firm as a partner from the hedge fund PanAgora Asset Management, where he oversaw $12 billion in equity assets under management as chief investment officer.

(Reporting by Lauren Tara LaCapra, Matthew Goldstein and Jennifer Ablan in New York; Editing by Gary Hill)